1. Field of the Invention
The present invention relates to a control device of an automatic transmission to be mounted on vehicles.
2. Description of the Related Arts
As a conventional transmission control technique, the one of making gear change using a motor has been known. In such transmission control technique, an automatic manual transmission of twin clutch type is adopted, and in which a shift fork is operated by two motors to select a gear to which a power is transmitted, whereby gear change is conducted. (For example, refer to the Japanese Patent Publication (unexamined) No. 177878/2007)
Further, as a control technique of correcting a torque error accompanied by the temperature change of a permanent magnet of a permanent magnet-type electric rotating machine, torque correction control technique with temperature change of a motor is disclosed, for example, in the Japanese Patent Publication (unexamined) No. 187155/2006. In the torque correction control technique with temperature change of the motor disclosed in the Japanese Patent Publication (unexamined) No. 187155/2006, based on a motor revolution number and a torque command value, a current command value is obtained referring to a torque current conversion map indicating the relationship between a torque value, a motor revolution number and a current value that has preliminarily been prepared, this obtained current command value is converted to a voltage command value, and a voltage command value with respect to a command torque is calculated.
Additionally, based on the mentioned torque command value, and referring to a torque voltage conversion map indicating the relationship between a torque value, a motor revolution number and a voltage value, a corrected voltage command value with respect to a command torque is calculated, a resistance change is calculated from a voltage difference between the voltage command value with respect to the mentioned command torque and the corrected voltage command value with respect to the mentioned command torque, further the amount of change of a current value is obtained from this resistance change, and letting this current change value a current correction value, a torque error is corrected.
Furthermore, as a conventional technique of calculating a coil resistance of a motor, a coil resistance calculation technique of a motor is disclosed, for example, in the Japanese Patent Publication (unexamined) No. 151790/2005. In this coil resistance calculation technique of a motor, when the motor is stopped, the same duty is held at least for not less than 0.5 seconds so as to prevent the rotation of the motor, thereby carrying a DC, a coil resistance is calculated from the electric current and the voltage of the motor, and from this calculated coil resistance, a coil temperature is estimated using resistance temperature characteristics of a coil.